Smart pressure relief valve

ABSTRACT

A method for identifying the potential location of a leak in a water heating system to one of a hot side and a cold side of the water heating system, the hot side of the water heating system receives incoming water at an inlet, the hot side of the water heating system including a bypass line connected in parallel to at least one heater line, a pressure sensor disposed on an exit of the hot side of the water heating system, the cold side of the water heating system receives incoming water at the inlet, a master valve disposed on an upstream location of the inlet, a first valve disposed on the bypass line and a second valve disposed on the at least one heater line, the method includes closing the master valve; opening the master valve; and closing the first valve and the second valve.

PRIORITY CLAIM AND RELATED APPLICATIONS

This non-provisional application claims the benefit of priority fromnon-provisional application U.S. Ser. No. 16/865,188 filed May 1, 2020and provisional application U.S. Ser. No. 62/842,549 filed May 3, 2019.Each of said applications is incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION 1. The Field of the Invention

The present invention relates to a pressure relief valve. Morespecifically, the present invention is directed to a pressure reliefvalve configured for detecting and servicing an overpressure conditionand also a leak in a fluid system to which the pressure relief valve iscoupled.

2. Background Art

Mechanical pressure relief valves have been used for relievingoverpressure of fluid systems for many years. With a mechanical pressurerelief valve, when an overpressure event occurs, there are noindications that may be obtained from the mechanical pressure reliefvalve as to the event/s or causes preceding the overpressure event.Routine overpressure events can indicate serious problems in a fluidsystem, e.g., a fluid of the fluid system may be overheated which cancause bursting of the fluid conductors which carry the fluid which inturn can cause equipment damage, explosions of the fluid system if theoverpressure is not relieved, e.g., if the pressure relief valvemalfunctions, and even loss of lives. While prior art pressure reliefvalves may function solely to relieve overpressure, they do not offer aglimpse into the reasons behind pressure relieving events. Further, theoperating pressure of fluid systems can vary from one system to another.Arbitrarily assigning a pressure relief valve setting to a pressurerelief valve can have one of at least two consequences. If the reliefpressure setting is disposed too high, a pressure relief valve may notrelieve a damaging overpressure when it is expected to function. If therelief pressure setting is disposed too low, a pressure relief valve maybe activated unnecessarily too frequently. Further, it is possible for apressure relief valve to fail to activate when an overpressure event hasoccurred.

U.S. Pat. No. 7,970,494 to Fima (hereinafter Fima) discloses a systemthat advantageously monitors a status of a relief valve coupled to awater heater or other pressure vessel. By monitoring the relief valve,the system can limit the energy and water wasted resulting from therelief valve's failure. The system can have first and second sensorsthat monitor a temperature and pressure within the relief valve, and awater flow from the relief valve, respectively. If the temperature orpressure within the relief valve exceeds predetermined thresholds, or awater flow from the relief valve continues for greater than apredetermined interval, the system can restrict a flow of gas, electriccurrent, or water to the water heater. Fima lacks a means forautomatically setting the relief pressure of a pressure relief valvebased on the operating pressure of the fluid system which its pressurerelief valve is configured to safeguard. Fima further lacks a pressurerelief valve capable of operating jointly with a fluid supply device,e.g., a water heater, which already has sensors capable of reportingreadings that can be used by a pressure relief valve.

There exists a need for pressure relief valve capable of adjusting itsrelief pressure thresholds based on the fluid or fluid system in whichthe pressure relief valve operates and is used to safeguard. Therefurther exists a pressure relief valve capable of providing tell-taledata or offering the stakeholder of a fluid system a glimpse of anoverpressure in the system that causes overpressure events or a pressurerelief valve indicating that the pressure relief valve has failed to actin response to one or more overpressure events such that correctiveactions can be taken to eliminate the pressure relieving events andreduce the frequency of unnecessary pressure relieving events. Therefurther exists a need for a pressure relief valve capable of usingexisting equipment or existing data from existing equipment to operate.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a method foridentifying the potential location of a leak in a water heating systemto one of a hot side and a cold side of the water heating system, thehot side of the water heating system receives incoming water at aninlet, the hot side of the water heating system including a bypass lineconnected in parallel to at least one heater line, a pressure sensordisposed on an exit of the hot side of the water heating system, thecold side of the water heating system receives incoming water at theinlet, a master valve disposed on an upstream location of the inlet, afirst valve disposed on the bypass line and a second valve disposed onthe at least one heater line, the method including:

-   -   (a) closing the master valve, obtaining a first pressure        indicated by the pressure sensor, obtaining a second pressure        indicated by the pressure sensor after a first delay from the        time the second pressure was obtained and comparing the second        pressure to the first pressure to yield a first difference in        pressure between the first pressure and the second pressure,        wherein if the second pressure is less than the first pressure,        a leak is said to have potentially occurred in one of the hot        side and the cold side;    -   (b) opening the master valve; and    -   (c) closing the first valve and the second valve, obtaining a        third pressure indicated by the pressure sensor, obtaining a        fourth pressure indicated by the pressure sensor after a second        delay from the time the third pressure was obtained and        comparing the fourth pressure to the third pressure to yield a        second difference in pressure between the third pressure and the        fourth pressure, wherein if the fourth pressure is less than the        third pressure, a leak is said to have potentially occurred in        the hot side and if the fourth pressure is substantially the        same as the third pressure and a leak has been determined in        step (a) to have potentially occurred in one of the hot side and        the cold side, a leak is said to have potentially occurred in        the cold side.

In one embodiment, the method further includes comparing the firstdifference to a first threshold and if the first difference is greaterthan the first threshold, the leak is said to have been potentiallycontributed by a water usage or a large leak. In one embodiment, thefirst threshold is about 5 psi. In one embodiment, the method furtherincludes comparing the second difference to a second threshold and ifthe second difference is greater than the second threshold, the leak issaid to have been potentially contributed by a water usage or a largeleak. In one embodiment, the second threshold is about 5 psi. In oneembodiment, the first delay is about 10 seconds. In one embodiment, thesecond delay is about 10 seconds. In one embodiment, if the secondpressure is about 0 psi, the leak is said to have been potentiallycontributed by an event selected from the group consisting of a waterusage or a large leak. In one embodiment, if the fourth pressure isabout 0 psi, the leak is said to have been potentially contributed by anevent selected from the group consisting of a water usage or a largeleak.

An object of the present invention is to provide a heating system andmethod for isolating the location of a leak in the heating system.

Whereas there may be many embodiments of the present invention, eachembodiment may meet one or more of the foregoing recited objects in anycombination. It is not intended that each embodiment will necessarilymeet each objective. Thus, having broadly outlined the more importantfeatures of the present invention in order that the detailed descriptionthereof may be better understood, and that the present contribution tothe art may be better appreciated, there are, of course, additionalfeatures of the present invention that will be described herein and willform a part of the subject matter of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other advantagesand objects of the invention are obtained, a more particular descriptionof the invention briefly described above will be rendered by referenceto specific embodiments thereof which are illustrated in the appendeddrawings. Understanding that these drawings depict only typicalembodiments of the invention and are not therefore to be considered tobe limiting of its scope, the invention will be described and explainedwith additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 is a diagram depicting a pressure relief valve adapted to carryout pressure relieving of a fluid system and also to detect and respondto a leak in the fluid system to which the valve is coupled.

FIG. 2 is a chart depicting a first period in which a pressure reliefvalve learns the operating pressure of a fluid system and a secondperiod in which the pressure relief valve is used to determine whetheran anomaly has occurred.

FIG. 3 is a diagram depicting a fluid system to which a pressure reliefvalve is coupled.

FIG. 4 is a diagram depicting a water system to which a pressure reliefvalve is externally coupled.

FIG. 5 is a diagram depicting a water system to which a pressure reliefvalve is internally coupled.

FIG. 6 is a diagram depicting the use of a pressure relief valveincluding a pressure sensor and a shutoff valve for detecting a hot sideleak and/or a cold side leak.

FIG. 7 is a flowchart depicting steps taken to locate a leak to either ahot side leak and/or a cold side leak.

PARTS LIST

-   2—pressure sensor-   4—flow sensor-   6—controller-   8—transceiver-   10—power-   12—actuator-   14—router-   16—internet-   18—pressure readings-   20—flow readings-   22—pressure readings during normal operations-   24—overly high pressure readings-   26—overly low pressure readings-   28—maximum pressure during normal operations-   30—minimum pressure during normal operations-   32—learning period-   34—application and learning period-   36—abnormal high pressure zone-   37—abnormally high pressure limit-   38—abnormal low pressure zone-   39—abnormally low pressure limit-   40—normal operating zone-   42—fluid system, e.g., water system, e.g., water heater-   44—inlet of water system-   46—outlet of water system-   48—shutoff valve-   50—shutoff valve controller-   52—water heater controller-   54—communication between water heater and shutoff valve-   56—communication between water heater and pressure relief valve-   58—communication between pressure relief valve and shutoff valve-   60—pressure relief valve-   62—toilet-   64—hot line faucet-   66—cold line faucet-   68—hot water line-   70—cold water line-   72—thermostatic valve-   74—mechanical pressure relief valve-   76—electronic pressure relief valve-   78—server-   80—mobile device-   82—scenario-   84—pump-   86—bypass valve-   88—valve actuator-   90—building wall-   92—heat exchanger-   94—flow line-   96—throttle valve-   98—fluid system-   100—indicator-   102—alarm

Particular Advantages of the Invention

In addition to relieving pressure of a water system, e.g., a waterheating system, the present pressure relief valve is capable ofdetermining a pressure pattern of a water system that indicates a leakin the water system. Further, the present pressure relief valve can beused for determining a pressure pattern of the water system thatindicates an overpressure condition in the water system.

As the present pressure relief valve is functionally connected topressure sensor, the pressure sensor is capable of detecting a conditionindicating a pressure relieving event is imminent. One or morecorrective measures may be taken to prevent such an event fromoccurring, e.g., by opening a faucet or other valves to drain a fluid ofthe fluid system which the relief valve is used to safeguard to relievethe pressure of the fluid. Even if a pressure relieving event does notoccur when no corrective measures are taken, the pressure patterns thatindicate a pressure relieving event is likely to occur may be used as atrigger to warn the stakeholder of the system that the fluid systemshould be altered or improved to mitigate this potential for newpressure relieving events.

In one embodiment, the pressure relief valve includes a mechanicalpressure relief valve tuned to relieve a pressure of a preset magnitude.In such an embodiment, the mechanical relief valve is used as a backupin case an electronic pressure relief valve of the fluid system fails.In one embodiment, the pressure relief valve includes only an electronicpressure relief valve having automatically adjustable high and lowpressure limits. The latter scenario allows the overpressure of a fluidsystem to be controlled using a common pressure relief valve as thepressure relief pressure can be automatically adjusted to the fluidsystem.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The term “about” is used herein to mean approximately, roughly, around,or in the region of. When the term “about” is used in conjunction with anumerical range, it modifies that range by extending the boundariesabove and below the numerical values set forth. In general, the term“about” is used herein to modify a numerical value above and below thestated value by a variance of 20 percent up or down (higher or lower).

FIG. 1 is a diagram depicting a pressure relief valve adapted to carryout pressure relieving of a fluid system and also to detect and respondto a leak in the fluid system to which the valve is coupled. The term“pressure relief valve” is used herein to mean a device useful forrelieving pressure of a fluid system and the device may include anelectronic pressure relief valve 76, a mechanical pressure relief valve74 or both. In case a mechanical pressure relief valve 74 is availablein addition to the electronic pressure relief valve 76, the mechanicalpressure relief valve 74 is used as a backup in case the electronicpressure relief valve 76 fails to actuate via actuator 12 to relieve anoverpressure event of a fluid in a fluid system 98 when it is requiredto do so. A pressure sensor 2 is functionally connected to a controller6 where the pressure sensor 2 is configured to take pressure readings 18of the fluid in the fluid system 98. In one embodiment, a flow sensor 4configured to take flow readings 20 of the fluid is a provided andfunctionally connected to the controller 6. The controller 6 andactuator 12 are powered by wall power or a portable power source, e.g.,a battery 10. Shown herein is an independent pressure relief valve. Itis also possible to use existing pressure and flow valves and controllerof an existing device, e.g., a water heater. A transceiver 8 aids thepressure relief valve in communicating with the outside world via arouter 14 that is connected via a modem with the internet 16. In oneembodiment, the controller 6 is configured to communicate with a remotemonitor, e.g., a server 78 or a mobile device 80, e.g., by transmittinga status signal regarding the pressure of the fluid of the fluid system98, an overpressure event of the fluid of the fluid system 98, and/oractuation of the actuator 12 in response to an overpressure event of thefluid of the fluid system 98. In one embodiment, an overpressure eventof the fluid of the fluid system 98 is relieved by automatically openinga faucet of the fluid system 98.

FIG. 2 is a chart depicting a first period 32 in which a pressure reliefvalve learns the operating pressure of a fluid system and a secondperiod 34 in which the pressure relief valve is used to determinewhether an anomaly has occurred. The first period 32 is a period inwhich the fluid system is expected to establish a norm against which ananomaly is compared and identified. Note that in the first period 32,the maximum pressure detected was the pressure level labeled 28 whilethe minimum pressure detected was the pressure level labeled 30. Thezone outlined or bounded by these two pressure levels 28, 30 aretherefore termed the normal pressure zone. The area between the highpressure level labeled 28 and an abnormally high pressure limit 37 istermed abnormal high pressure zone 36 and the area between the lowpressure level labeled 30 and an abnormally low pressure limit 39 istermed abnormal low pressure zone 38. The abnormally high pressure limit37 can be established by adding a pre-defined gap of a particularmagnitude or a pre-defined percentage of the high pressure level 28.Likewise, the abnormally low pressure limit 39 can be established byadding a pre-defined gap of a particular magnitude or a pre-definedpercentage of the low pressure level 30 in a direction opposite that ofthe abnormally high pressure limit 37. It shall be noted that theoverpressure condition as shown in zone 36 and the underpressure or leakcondition 38 do not occur simultaneously but rather these conditions aremutually exclusive although they are both shown in FIG. 2 . Byestablishing a normal operating zone 40 for a fluid system in whichpressure readings 22 during normal operations lie, appropriate upper andlower pressure limits may be established automatically for the fluidsystem. These limits may alternatively be set without establishing thenormal pressure zone if desired and if the normal pressure zone isalready known. Any pressure behavior, observed post establishment of thenormal operating zone 40, that deviates from the established normalpressure zone will be deemed unacceptable, e.g., overly high pressurereadings 24 and overly low pressure readings 26. In one embodiment, thefluid system further includes a pressure relief valve and the actionincludes activating the pressure relief valve to relieve an excessivepressure build-up of the fluid system. If the former readings aredetected, an electronic pressure relief valve may be activated such thatthe pressure level does not continue to rise to a level sufficient toactivate a mechanical pressure relief valve of the fluid system. If thelatter readings are detected, a fluid flow of the fluid system may beterminated by closing a valve. In this example, the operating parameterestablished in the learning phase of the pressure relief valve is themagnitude of the fluid pressure of a fluid flow of a fluid system. Itshall be appreciated that the presence of a low pressure condition canindicate a leak in a fluid system coupled with a present pressure reliefvalve. A small leak is characterized by a drop in pressure of a fluid inthe fluid system but nonetheless sustained at a consistent level overtime. A growing leak however is characterized by a continuous drop inpressure of the fluid of the fluid system over time. Both of these leakconditions can be detected in the present pressure relief valve as thecontroller is configured to determine whether a drop in pressure hasoccurred over time.

Therefore, it can be summarized that the present pressure relief valvecan be used for monitoring a fluid system for an overpressure or a leakcondition with the aid of a sensor and a controller. The sensor isuseful for monitoring the pressure of a fluid of the fluid system toproduce signals over a period; and the controller is configured forreceiving the signals over the period, establishing an operatingpressure zone corresponding to the signals over the period, theoperating pressure zone being representative of a normal operation zoneof the fluid system. Upon establishing the normal operation zone of thefluid system, the pressure relief valve is ready for use in respondingto overpressure or leak conditions. Any new sensor signals fallingoutside the normal operation zone are potentially indicating anoverpressure or a leak condition. In one embodiment, the sensor is apressure sensor configured for reporting the pressure of the fluid ofthe fluid system. In one embodiment, the action includes communicating awarning, e.g., by creating a text message with the controller andsending the message by means of Short Messaging Service (SMS) via thetransceiver 8, router 14, internet 16 to a text-enabled mobile device 80of a stakeholder of the fluid system. The stakeholder may then decide onthe next steps to take in response to this warning and may do one ormore number of things. The stakeholder may simply inspect the fluidsystem in person especially when the anomaly may have led to potentialdamages to the fluid system and properties surrounding the fluid system.In cases where no properties damages and no immediate danger to livesare expected, the fluid pressure data may be examined remotely. As thefluid pressure data may be cached by the controller or communicated andcached at the server 78, the fluid pressure data taken during periodsbefore conditions are raised, the cause for an overpressure or a leakcondition may be determined.

Alternatively or additionally, pressure patterns or time derivatives ofpressure readings, e.g., the rate of change of pressure readings, may beestablished or calculated and used as a baseline for anomaly detectionin the second period 34 instead of simply the magnitude of the pressurereadings. For instance, if the magnitude of the rate of change ofpressure over a time period, dP/dt, exceeds a pre-determined criticalpressure rise rate, where dP represents a change in pressure of thefluid system and dt represents the time period over which the change inpressure of the fluid system takes place, a warning is communicated to astakeholder of the fluid system, indicating this behavior. In oneembodiment, this behavior serves a trigger for an action that warns thestakeholder that a problem may exist in the fluid system and a furtherinvestigation for the root cause of the behavior is warranted. In oneembodiment, if this behavior occurs in conjunction with the pressurereading/s falling within the abnormal high pressure zone 36 or theabnormal low pressure zone 38, the confidence that a severe overpressureor underpressure condition has occurred is increased and that animmediate response to the situation is warranted. In one embodiment,this behavior alone is used by the fluid system as a trigger to respondas if an overpressure condition or a leak condition had occurred.

Further, if flow sensor data is also available as obtained via the flowsensor 4, it can be reviewed in conjunction with the pressure data todetermine whether raised conditions are urgent. For instance, if theflow sensor 4 shows that a fluid flow continues even after the fluidsystem has been shut down, the raised conditions may indicate a leak ordamage to the fluid system that causes a leak to occur and continue.

FIG. 3 is a diagram depicting a fluid system to which a pressure reliefvalve 60 is coupled. Here, the fluid system is a hot water system wherea water heater 42 receives an inlet 44 of unheated water from a coldwater line 70 and provides a hot water output in hot water line 68 toend users at faucets 64. Unheated water end users receive water atfaucets 66. Thermostatic valves 72 each allows mixing of unheated waterwith heated water to temper the hot water line 68 before the mixturereaches an end user. The cold water line further supplies water to atoilet 62. In the embodiment shown, the system further includes a valve48 that regulates a flow of fluid to the fluid system, a valve actuatorthat operates the valve, wherein the controller 50 controllablycommunicates with the valve actuator as a function of the new signal. Inthis embodiment, a mechanical pressure relief valve 74 is provided inaddition to an electronic pressure relief valve 76. In one embodiment,the controller 50 is configured to receive wall power. In anotherembodiment, the controller 50 is configured to receive power via aportable power source, e.g., a battery. In one embodiment, thecontroller 50 is configured to transmit a status signal over a wire toone or more devices outside of the pressure relief valve 60, e.g., anindicator 100, e.g., a flashing light, etc. In another embodiment, thecontroller is configured to transmit a status signal wirelessly todevices outside of the pressure relief valve 60, e.g., via a ShortMessage Service (SMS) message, email, etc. If a water heater 42 alreadyhas a pressure sensor, the pressure relief valve 60 can be configured toobtain pressure readings from the water heater 42 and does not need itsown pressure sensor. Computations related to monitoring of the readingsand decision making for any actions that need to be taken based on thereadings can be made locally in controller 6, controller 52 of the waterheater or controller 50 of the shutoff valve 48 or remotely in remoteservers as shown elsewhere herein. In one embodiment, the pressurerelief valve 60 is at least partially disposed within a housing ofcontroller 6, making the pressure relief valve 60 compact in itsfunction and requires no interactions with other devices locally.Communication 54 between water heater 42 and shutoff valve 48,communication 56 between water heater 42 and pressure relief valve 60and communication 58 between pressure relief valve 60 and shutoff valve48 can be made possible either by wire or wirelessly.

In one embodiment, the system further includes an alarm 102 functionallycoupled to the controller 6, wherein the controller 6 is furtherconfigured to activate the alarm 102 to catch a stakeholder's attentionto a potential overpressure or leak problem. In one embodiment, thealarm includes a status light. In one embodiment, the alarm includes anaudio emitter to further serve as an alert broadcaster to a stakeholder.In one embodiment, the system further includes a reset switchfunctionally coupled to the controller, such that actuating the resetswitch deactivates the alarm. An alarm is deactivated when thestakeholder has been informed and the alarm is no longer needed. In oneembodiment, the sensor 2 is configured to wirelessly communicate withthe controller 6 if the sensor 2 is not disposed within the same deviceas the controller 6. In one embodiment, the fluid system is a fluidheater 42, wherein the functionalities of controller 6 is integratedinto a circuitry of the fluid heater 42, i.e., in controller 52. In oneembodiment, the controller 6 is a component independent from a circuitryof the fluid system 42. An overpressure condition in the fluid system isdetected and serviced by the relief valve 60. In the present pressurerelief valve, a leak condition as shown in scenario 82 can be detectedby the pressure relief valve 60. If a catastrophic leakage is determinedto have occurred, e.g., if the rate of pressure drop exceeds apre-determined threshold, shutoff valve 48 can be activated to preventand contain prevent property damage during to this catastrophic leakage.In the event that an overpressure condition or a leak condition has beendetected, the fluid system is turned off. For instance, if a waterheater 42 is part of the fluid system, the water heater 42 will cease toproduce heated water.

FIG. 4 is a diagram depicting a water system to which a pressure reliefvalve 60 is externally coupled to a fluid system, e.g., a water heater42. Here, it shall be seen that the pressure relief valve 60 is disposedoutside of the enclosure of the water heater 42 and on the outlet 46 offluid system. The pressure relief valve 60 may include its own pressuresensor 2, flow sensor 4 and controller 6 and can function as a pressurerelief valve even without any interactions with or inputs from the waterheater 42. In one embodiment, the controller 6 of the pressure reliefvalve 60 is configured to interact with one or more sensors, e.g.,pressure sensor and flow sensor, of the water heater 42, removing theneed for the pressure relief valve 60 to have those sensors of its own.FIG. 5 is a diagram depicting a water system to which a pressure reliefvalve 60 is internally coupled. Here, all of the required sensor/salready exist in the water heater 42. The controller can be the samecontroller used for the water heater 42. If a mechanical and/orelectronic pressure relief valve is not already available for the waterheater 42, they can be provided and installed in the water heater 42. Inthe embodiment shown in both FIGS. 4 and 5 , the pressure relief valve60 includes a flow sensor. In an embodiment not shown, the pressurerelief valve 60 relies on a water heater for a flow sensor. Armed with aflow sensor, it is possible to determine the usage of the fluid system.For instance, flow rates of the fluid system may be correlated to avariety of equipment in a fluid system. For instance, if flowrates of aparticular size and duration can be determined to correspond to one ormore toilets, e.g., by observing flowrates over durations, the adequacyof the number and/or placement of bathrooms in a building can bestudied. As an example, flows of about 1.6 gallons over a duration ofabout 10 seconds may be attributed to toilet flushes while flows of overabout 10 gallons over a duration of over a duration of about 2 minutesmay be attributed to showers or baths.

FIG. 6 is a diagram depicting the use of a pressure relief valveincluding a pressure sensor and a shutoff valve for detecting a hot sideleak and/or a cold side leak of a heating system. Depicted in FIG. 6 isa water heater 42, e.g., one installed in a building. The water heaterreceives unheated water from a supply through the building wall 90 andsupplies heated water to a point of delivery, e.g., faucet 64. For sakeof simplicity and clarity, only one example of a water heater is shown.However, the same strategy shown herein for detecting a hot side leakand/or a cold side leak is applicable to water heaters of otherconfigurations. The water heater 42 includes two heat exchangers 92disposed in parallel, each heat exchanger 92 receiving a flow via athrottle valve 96 before merging into a flow from flowlines 94 that maybe supplied at the water heater outlet 46 or recirculated through thebypass valve 86 that is also disposed in parallel to the heat exchangers92. In one mode of the water heater 42, the unheated water flow maybypass the heat exchangers 92, at least partially to flow through thebypass valve 86 to be mixed with effluent from at least one of the heatexchangers 92. A main shutoff valve 48 is typically disposed inside abuilding on or near an interior wall 90. A pump 84 is disposed upstreamof the throttle valves 96 and just past a fluid conductor on which thebypass valve 86 is disposed. A pressure sensor 2 is disposed at theoutlet 46 of the water heater 42. The shutoff valve 48 may be manuallyoperated or it may be coupled with a valve actuator 88 for a motorizedoperation. Here, the valve actuator 88 controls whether unheated watercan be supplied to the water heater 42 and to faucet 64. It is notalways apparent where a leak occurs when it does occur. It is alsobeneficial to recognize a leak early so that it does not lead to a largeproblem later.

Disclosed herein is a first method for narrowing down the location of aleak to whether the leak has occurred in the hot side or the cold(unheated) side. In this embodiment, in determining whether a leak hasoccurred at the hot side or cold side, the shutoff valve 48 is closedalong with all of the valves in the water heater 42, i.e., the bypassvalve 86 and throttle valves 96. If a pressure decay is observed inpressure sensor 2, a hot side leak is deemed to have occurred. A servicepersonnel can then focus on locating the leak in the hot side or thefluid conductors between the valves in the water heater 42 and point ofuse, e.g., the faucet 64 in this case. However, if no pressure decay isfound, then valves 86 and 96 are opened. If a pressure decay is found,then a cold side leak is deemed to exist. A hot side leak is notexclusive of a cold side leak, i.e., a hot side leak can occurconcurrently with a cold side leak. Therefore, even if a hot side leakhas been identified to exist, one should also look for a cold side leak.If a cold side leak is determined to be present, a service personnelshould focus on locating the leak in the cold side or the fluidconductors between the valves in the water heater 42 and the shutoffvalve 48 and the entire cold fluid conductor up to the point of use,e.g., the faucet 64 in this case. It shall be noted that in detecting ahot side leak and/or a cold side leak, no additional plumbing has beenrequired with the present method. Further, if exists, a pressure trend,e.g., a growing pressure trend seen in pressure sensor 2, can bereported to a stakeholder of the water heater 42 before a catastrophicrelief valve event can occur so that a corrective action can be taken.Yet further, in any water heater or flow line equipped with a flowsensor, flow usages and events, e.g., kitchen faucet usages and toiletflushes can be estimated and flow data can be gathered for furtheranalysis.

Disclosed herein is a second method for narrowing down the location of aleak to whether the leak has occurred in the hot side or the cold(unheated) side as applied to the water heating system shown in FIG. 6 .The water heating system as shown in FIG. 6 essentially receivesincoming water at an inlet with the hot side of the water heating systemincluding a bypass line connected in parallel to at least one heaterline. A pressure sensor is disposed on an exit of the hot side of thewater heating system. The cold side of the water heating system receivesincoming water at the inlet. A master valve 48 is disposed on anupstream location of the inlet. A first valve 86 is disposed on thebypass line and a second valve 96 is disposed on the at least one heaterline. Here, there are two heater lines shown in FIG. 6 . In thisembodiment, in determining whether a leak has occurred at the hot sideor cold side, the shutoff valve 48 is closed. A first pressure indicatedby pressure sensor 2 is obtained. A second pressure, also as indicatedby pressure sensor 2, is then obtained after a first delay from the timethe second pressure was obtained. The second pressure is then comparedto the first pressure to yield a first difference in pressure betweenthe first pressure and the second pressure. If the second pressure isless than the first pressure or a pressure decay, e.g., by about 2 ormore psi, has been observed, a leak is said to have potentially occurredin one of the hot side and the cold side. The master valve 48 is thenopened and the first valve 86 and second valves 96 are closed. A thirdpressure as indicated by pressure sensor 2 is then obtained. A fourthpressure as indicated by pressure sensor 2 is obtained after a seconddelay from the time the third pressure was obtained. The fourth pressureis then compared to the third pressure to yield a second difference inpressure between the third pressure and the fourth pressure. If thefourth pressure is less than the third pressure or a pressure decay,e.g., by about 2 or more psi, has been observed, a leak is said to havepotentially occurred in the hot side. If the fourth pressure issubstantially the same as the third pressure (or the fourth pressure iswithin about 1 psi of the third pressure) and a leak has been determinedearlier to have potentially occurred in one of the hot side and the coldside, a leak is said to have potentially occurred in the cold side. FIG.7 is a flowchart summarizing steps taken to locate a leak to either ahot side leak and/or a cold side leak.

In one embodiment, the second method further includes comparing thefirst difference to a first threshold and if the first difference isgreater than the first threshold, the leak is said to have beenpotentially contributed by a water usage or a large leak. In oneembodiment, the first threshold is about 5 psi. In one embodiment, thesecond method further includes comparing the second difference to asecond threshold and if the second difference is greater than the secondthreshold, the leak is said to have been potentially contributed by awater usage or a large leak. In one embodiment, the second threshold isabout 5 psi. Ideally, each of the methods disclosed herein for locatinga leak should be carried out while water is not demanded. However, thatis not always possible. Therefore, it shall be noted that a mechanismfor narrowing down the cause for water movements has been provided. Inone embodiment, the first delay is about 10 seconds. In one embodiment,the second delay is about 10 seconds. In one embodiment, if the secondpressure is about 0 psi, the leak is said to have been potentiallycontributed by an event selected from the group consisting of a waterusage or a large leak. In one embodiment, if the fourth pressure isabout 0 psi, the leak is said to have been potentially contributed by anevent selected from the group consisting of a water usage or a largeleak.

The detailed description refers to the accompanying drawings that show,by way of illustration, specific aspects and embodiments in which thepresent disclosed embodiments may be practiced. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice aspects of the present invention. Other embodiments may beutilized, and changes may be made without departing from the scope ofthe disclosed embodiments. The various embodiments can be combined withone or more other embodiments to form new embodiments. The detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined only by the appended claims,with the full scope of equivalents to which they may be entitled. Itwill be appreciated by those of ordinary skill in the art that anyarrangement that is calculated to achieve the same purpose may besubstituted for the specific embodiments shown. This application isintended to cover any adaptations or variations of embodiments of thepresent invention. It is to be understood that the above description isintended to be illustrative, and not restrictive, and that thephraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Combinations of the above embodimentsand other embodiments will be apparent to those of skill in the art uponstudying the above description. The scope of the present disclosedembodiments includes any other applications in which embodiments of theabove structures and fabrication methods are used. The scope of theembodiments should be determined with reference to the appended claims,along with the full scope of equivalents to which such claims areentitled.

What is claimed herein is:
 1. A method for identifying the potentiallocation of a leak in a water heating system to one of a hot side and acold side of the water heating system, the hot side of the water heatingsystem receives incoming water at an inlet, the hot side of the waterheating system comprising a bypass line connected in parallel to atleast one heater line, a pressure sensor disposed on an exit of the hotside of the water heating system, the cold side of the water heatingsystem receives incoming water at the inlet, a master valve disposed onan upstream location of the inlet, a first valve disposed on the bypassline and a second valve disposed on the at least one heater line, saidmethod comprising: (a) closing the master valve, obtaining a firstpressure indicated by the pressure sensor, obtaining a second pressureindicated by the pressure sensor after a first delay from the time saidfirst pressure was obtained and comparing said second pressure to saidfirst pressure to yield a first difference in pressure between saidfirst pressure and said second pressure, wherein if said second pressureis less than said first pressure, a leak is said to have potentiallyoccurred in one of the hot side and the cold side; (b) opening themaster valve; and (c) closing the first valve and the second valve,obtaining a third pressure indicated by the pressure sensor, obtaining afourth pressure indicated by the pressure sensor after a second delayfrom the time said third pressure was obtained and comparing said fourthpressure to said third pressure to yield a second difference in pressurebetween said third pressure and said fourth pressure, wherein if saidfourth pressure is less than said third pressure, a leak is said to havepotentially occurred in the hot side and if said fourth pressure issubstantially the same as said third pressure and a leak has beendetermined in step (a) to have potentially occurred in one of the hotside and the cold side, a leak is said to have potentially occurred inthe cold side.
 2. The method of claim 1, further comprising comparingsaid first difference to a first threshold and if said first differenceis greater than said first threshold, said leak is said to have beenpotentially contributed by an event selected from the group consistingof a water usage or a large leak.
 3. The method of claim 2, wherein saidfirst threshold is about 5 psi.
 4. The method of claim 1, furthercomprising comparing said second difference to a second threshold and ifsaid second difference is greater than said second threshold, said leakis said to have been potentially contributed by an event selected fromthe group consisting of a water usage or a large leak.
 5. The method ofclaim 4, wherein said second threshold is about 5 psi.
 6. The method ofclaim 1, wherein said first delay is about 10 seconds.
 7. The method ofclaim 1, wherein said second delay is about 10 seconds.
 8. The method ofclaim 1, wherein if said second pressure is about 0 psi, said leak issaid to have been potentially contributed by an event selected from thegroup consisting of a water usage or a large leak.
 9. The method ofclaim 1, wherein if said fourth pressure is about 0 psi, said leak issaid to have been potentially contributed by an event selected from thegroup consisting of a water usage or a large leak.